DRESSER, Wis. (AP) — A 2-year-old Wisconsin boy who was found dead in the trunk of a car had the key to the vehicle with him, the family’s pastor said Saturday.

Isaiah Theis had that key and several other sets of keys with him when a deputy found his body Wednesday night, the Rev. Rick Van Gundy told The Associated Press. Van Gundy said he got the information from the Theis family but declined to be more specific, because of the sensitivity of the situation.

“This is breaking the heart of somebody who has a broken heart,” said Van Gundy, pastor of St. Peter’s Community Church in Dresser. “It’s that much of a devastation to them that you can’t even put a word to it.”

The deputy found the boy in the trunk of a customer’s car on his parents’ property near Centuria, where the boy’s father runs an auto repair business. Preliminary autopsy results released Friday said Isaiah likely died of hyperthermia — a condition in which the body temperature spikes — due to Wednesday’s blistering heat.

Polk County investigators have not yet said how Isaiah, who disappeared Tuesday night, got in the trunk. Sheriff Peter Johnson did not immediately return a phone call from the AP on Saturday.

The news about the keys was first reported Friday night by KSTP-TV. Van Gundy told the station he had personally shined a flashlight inside the car and looked under it when he joined the search Tuesday night, but that it never crossed anybody’s mind to unlock the trunk.

Officials with the sheriff’s department have made similar statements. Investigators said they presumed Isaiah had wandered off while playing with his brother Tuesday night because he had a tendency to do that.

About 2,450 civilian volunteers helped search the fields and woods surrounding the family’s home, about 60 miles northeast of St. Paul, Minn., throughout the day Wednesday. But nobody looked into the trunk until the car’s owner came to retrieve it Wednesday night.

Van Gundy said he was not surprised that Isaiah might have been able to use the keys to get into the trunk.

“He’s an exceptionally smart little boy,” he said, adding that he would often watch his father repairing cars and had picked up his father’s mechanical aptitude. “If he saw you once he could emulate it, he could copy it.”

The Theis family is still hurting deeply, Van Gundy said, describing them as “emotionally and physically tired, soul-weary but blessed.”

Isaiah’s funeral will be held in the coming week, but details were not settled, he said.